Investigators are said to have collected CCTV images from the entrance to Belgrad Forest to the north of the city amid fears the US-based Saudi writer’s body was dumped there.

After tracing the route of the convoy of cars which left the Saudi consulate on the day the journalist went missing, the search has moved to woodland near the city of Yalova, a 90-kilometre (55 mile) drive south of Istanbul.

They are reportedly also preparing to ‘excavate’ a villa in Yalova province, where one of the vehicles linked to the Saudi ‘hit squad’ was seen, according to Turkish media.